Percussion tool



May 20, 1952 E. H. DlcKENsoN PERCUSSION TOOL Filed Dec.

INVENTOR BEYRNEST H. DI OKENSON l I I I I I l l l I I I F l l Il HIS ATTORNEY.

Patented May 20, 1952 Union of South Africa, assigner Ito Ingersoll- Rand Company, New York, N. Y., a corporation of New Jersey Application December 1, 1948, `Serial No. 62,859

`4 Claims. (Cl. 121-7) This invention relates to percussion tools and moreparticularly to percussion tools of the pneumatic-rock drill type.

One object of my invention is to provide a mechanism whereby rotary movement may be imparted to the working implement of a rock drill in which an element extends through the drill 'for transmitting the blow energy of the piston to the workingimplement.

Another-object of my invention is to minimize the wear on the end of the working implement exposed to the blows ofthe element extending through the rock-drill. y

Other objects will become obvious hereinafter.

In the accompanying drawing showing a preferred embodiment of the invention and in which' similar reference characters refer to similar parts:

Figure ll is a vertical elevationVpa'rtlyfin section, of a, rock drill constructed in accordance with the practice of the invention,

Figure 2 is a transverse view taken through Figure 1 along the line 2--2 looking inthe direction of the arrows, and l Figure 3 is a sectionalelevation of an alternate form of front head -construction for the drill shown in-Figure l.

Referring to the drawings, I designates, ,in general, a pneumatic rock drillcomprising acasing I I having a chamberIZ in which reciprocates the hammer piston I3 for actuating a working implement I4. Motive fluid, such as compressed air, for actuating the piston I3 is conducted ,alternately to the forward and rearward ends of the chamber I2 through passages I5 and I6, respectively, controlled by a valve, such as the oscillating valve I'I, in the valve chest I8 that forms a closure for the rearward end of the chamber I2.

The piston I3 is provided with a central bore I9 for the reception of an anvil rod 20 extending through the drill and serving as a means for transmitting the rotary movement and the blow energy of the piston I3 to the working implement I4. In furtherance to this end, the rod 20 is provided with an impact shoulder 2| slidably mounted in an opening 22 in the front head of the drill I 0 and extending into the chamber I2 to receive the blows of the piston I3. The front end lportion of the opening 22 is somewhat enlarged'for the reception of an external flange 24 on the -rod 20 that cooperates with the shoulder forming the rearward end of the enlarged portion 23 to limit rearward movement of the rod 20. Forward movement of the anvil rod 20 is limited by a cap 25 threaded on the front end of the 2 rock drill and having a Vrim 4'portion 216 lying -in the path of the `flange-24.

In accordance with .the .practice of the invention, rotary motion is imparted to the working implement I4 through therod `2l] rotatedbyithe piston AI3 which, in turn, is rotated by ratchet mechanism mounted intermediate .the ends of the casing tI I and encircling the piston I3.

The ratchet mechanism 2l comprises anlannular member 28 in which are mounted spring pressed dogs `29 that extendinwardly to engage external teeth :30 on a ring 3I .positioned coaxial with` and withinthe member 28 andhaving internal splines 32 that ride in .spiralfflutes ,'33 .inthe periphery of the piston I3. The flutes .33 terminate at one end in the rearward end surface of the piston I3 in order to permit the piston to be mounted ,in the preferred unitary or solid type ring v3I-that is, withthis flute arrangement, the

inwardly extended splines 3'2 may be inserted in the .open ends of the Vliutes 33 Vand the ring 3l slid along the piston I3 to its operative position.

With .this arrangement, the ratchet 21 will engage and rotate the piston I`3-during`longitudinal movement thereof in one direction, as shown, on its back stroke, and permit it to run free during longitudinal movement in the opposite or .forwardly direction. Thus, by providing means for transmitting vrotary motion .from the vpiston to the anvil rod 20, such as the flatted surfaces r3B formed ina cap member 4I] threaded in bore I9 that cooperate with similar .flatted surfaces 35 on the rod 20, the working implement will be rotated .during the backward stroke of the piston and will .travelfreeon the forward stroke thereof. In order to facilitate mounting the vratchet mechanism 2 `in the casing II, the intermediate portion 36 vof the casing is somewhat enlarged to form a ratchet chamber 3Ifor themechanisrn 2l; and the casing II ,is split at this junctureand held together `by'bolts 38. Thus, to assemble the drill, it is merely knecessary to insert the piston in the ratchet orrotating mechanism 2'I, .as previously described, then place the mechanism 2'I in the-chamber 31 and bolt the casing together. In the .form .of the invention shown, pressure fluid fis exhausted from .the chamber VI2 through exhaust `,ports .39 positioned in the casingon -the opposite sides of the enlarged portion 36 and, so positioned, the ports 39v communicate with the utes 33 during at least a portion of every piston cycle. In order to prevent leakage of pressure fluid along the piston II through the flutes 33 and thence to the atmosphere, the capping member 40 is disposed at the rearward end of the piston I3 and is provided with a ange 4I of slightly greater diameter than the piston, so that it overlies the open ends of the flutes 33 to seal against leakage of pressure fluid along the piston. The capping member 49, so positioned and so constructed, also serves to guide the piston and to minimme the wear of the piston due to rubbing against the material bounding the chamber I2.

In the embodiment of the invention shown, the rod 20 also serves to define a channel through the drill for the passage of cleansingfluid through the drill hole and to this end, is provided with a central passage or bore 44 which registers with a similar passage 45 in the working implement I4 threaded in the forward end of the rod. The rearward end portion of the rod 20 extends slidably through a hole 46 in the valve chest I8 and thence into a bore 41 in a plug 48 mounted on the back head of the drill.

Thus, by providing means, such as the seal 49 and the associated atmospheric duct 50 in the cap 48, to prevent the leakage of air or other motive fluid from the valve chest I8 into the passage 44, a cleansing fluid may be passed through the drill I in either direction to remove cuttings from the drill hole. That is, by passing a cleansing iiuid, such as water, through the drill and into the drill hole, the cuttings are washed from the hole; or if dry or dustless drilling is desirable, a negative pressure source, such as a vacuum pump (not shown), is communicated with the passage 44 to draw the cuttings from the drill hole through the rock drill.

Such an arrangement provides a highly important advantage due to the various conditions under which the drill may be required to operate. For example, under one condition, such as stopping, or overhead drilling, dry drilling would be advantageous whereas under another condition wet drilling may be preferable. In the present invention, shifting from one mode of drilling to the other merely necessitates changing the pressure source for the cleansing fluid.

In the alternate front head construction (shown in Figure 3), a sleeve or chuck 5I is threaded on the forward end of the anvil rod 20 and a removable impact washer 52 provided with a central perforation or opening 53 that registers with the passages 44 and 45 in the anvil rod and working implement respectively, is interposed between the opposed ends of the chuck I and the anvil rod 20. The washer 52, so positioned, serves to transmit longitudinal movement imparted to the anvil rod by the piston I3 to the working implement I4. Thus, a relatively inexpensive and readily replaceable impact washer eliminates direct contact between the end portions of the working implement and anvil rod and minimizes the wear of said ends.

It is obvious from the previous discussion that a rock drill constructed in accordance with the practice of this invention is provided with a new and simple arrangement for rotating the working implement of a rock drill, and it is also clear that such an arrangement precludes any possibility of intermixing of the cleansing and motive fluid by providing a seal at the rearward end of the rock drill.

While I have shown and described specic forms of my invention, it is to be understood that various changes and modifications may be made without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. In a rock drill, the combination of a reciprocable working implement and a motor having a reciprocatory hammer piston for actuating the Working implement, means extending through the hammer piston for transmitting the blows of the hammer piston to the working implement, means for securing the first mentioned means to the working implement, a mechanism for rotating said piston, and means on the hammer piston and on the first mentioned means slidably interlocked with each other for transmitting the rotary movement of the piston to the rst said means.

2. A percussion tool including a casing having a chamber therein, a reciprocative piston in said chamber, a working implement, means extending through said piston for transmitting the blow energy of the piston to the working implement, a mechanism for rotating the piston, and means on the piston and on the rst said means slidably interlocked with each other for transmitting the rotary movement of the piston to the first said means.

3. A rock drill, comprising a casing having a compression chamber therein, a reciprocative piston in said chamber having a central passage therethrough and longitudinally disposed peripheral grooves, a working implement actuated by the piston, an anvil rod extending slidably through said passage and in interlocking engagement with the piston, an impact shoulder on said rod for the reception of the blows of the piston, means at an end of said anvil rod for securing the working implement thereto, and a ratchet mechanism encircling said piston and having splines in sliding engagement with said grooves, said mechanism ybeing arranged to impart rotary motion to the piston during longitudinal movement of the piston in one direction and to permit the piston to run free during longitudinal movement in the opposite direction.

4. A pneumatic rock drill comprising, a casing having a chamber therein, a reciprocative hammer piston in said chamber having a passage therethrough, a member extending through said passage in slidable interlocking engagement with the piston, grooves in the periphery of the piston opening into an end surface of the piston, a ratchet mounted on said casing slidably interlockcd with said grooves, and a cap overlying such end surface of the piston and the end of the grooves for preventing the leakage of pressure fluid along said grooves.

ERNEST H. DICKENSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 308,523 Sergeant Nov. 25, 1884 618,324 Blum Jan. 24, 1899 1,183,257 Waugh May 16, 1916 1,588,441 Browne June 15, 1926 2,081,919 Gartin June 1, 1937 2,298,503 Osgood Oct. 13, 1942 

